Electric impulse motor device



1953 M. MORRISON ELECTRIC IMPULSE MOTOR DEVICE 2 Sheets-Sheet 1 Filed Aug. 16, 1949 INVENTOW 71W NOV. 17, 1953 MORRISON 2,659,853

ELECTRIC IMPULSE MOTOR DEVICE Filed Aug. 16, 1949 2 Sheets-Sheet 2 INVENTOR wwo Patented Nov. 17, 1953 UNITED STATES PATENT OFFICE 2,659,853 ELECTRI IMPULSE MOTOR DEVICE Montford Morrison, Upper Montclair, N. J.

Apnli et onA su t 16, 9! Se l N 1 0.59

3 Claims. 1

The present invention relates generally to electric current impulse motors, it relates more par.- ticularly to impulse stepping devices, and it re,- lates'more specifically to impulse counters.

Among the objects of the invention is to pro vide a rotating armature, which turns exactly a predetermined number of an ular degrees for each impulse of current fed through the motor.

A further object of the invention is to provide a transducer of electric current impulses into definite measured rotary motion without the use of intermediary mechanical devices.

A further object of the invention is to provide a stepping switch operatin mechanism which has no mechanical stepping mechanism in it.

A further object of the invention is to provide an electrical impulse counter operating mechanism which has no ratchets nor latches in it.

ur h r an other b c wi e ointed ou and obvious to those skilled in the art through the course-of the specification,

The generic nature of the invention resides importantly in an electric motor structure comprising a salient pole stator and a salient pole rotor having pole structure providing lesser magnetic operating flux reluctance for rotor operate ing in one direction than in the other, under direct current impulse operation,

A further nature of the invention resides in a dual magnetic path for the flux in the rotor which is caused to alternate in effective direction thereby causing rotor operation in a predetermin d rec n for a ser es of di ect urre t impulses.

A further nature of the invention resides in having a constant rotor position holding flux which causes the rotor to be held in any posi-v tion to which ithas been rotated. A further nature of the invention resides in forming the cooperating poles of the stator and rotor to cause the rotor to move in one direc: tion and in one direction only.

A further nature of the invention resides in having a constant magnetic field which in cooporation with the structural elements of the invention, causes the rotor to move through a defi nite predetermined angular displacement for each impulse received by the stator winding.

Referring to the drawing, Fig. l is an embodiment of the invention, with some of the shaft bearings removed for clearness, Fig. 2 is a section of Fig. 1, taken through the vertical center line thereof, Fig. 3 is a second embodiment of the invention, Fig. 4 is connection diagram, which when applied to Fig. 1 constitutes a third embodiment of the invention, and Figs. 5, 6, V and 8 are drawings useful in teaching'the art of pole structure employed in the invention.

Referring to .Figs. 1 and 2, I is a shaft carryins a rotor 2 having a multiplicity of s'alientpoles 2 such as 3, with interpolar spaces such as l, the structural-forms of these poles and spaces will be disclosed in connection with Figs. 5-8 inclu SlVB.

Fig. 1, 5 is a stator member having D018 equ ang'ularly spaced with the poles of the rotor, and 6 is a stator member having poles equi-angularly spaced with the poles of the rotor. Stator mem bers 5 and 6 are so related angularly that when the poles of 5 register with the poles of the rotor 2, the poles of 6 register with the interepolar spaces of rotor 2, as shown in the figureand obviously when the poles of 6 register with the poles of the rotor, the poles of 5 register with the inter-polar spaces of the rotor.

Stator member 5 forms the core of magnet coil 1', and which protrudes through said coil form: ing a magnetic pole 8. Likewise stator member 6 forms the core of magnet coil 9, and protrudee through said coil forming a magnetic pole Ill.

Figs. 1 and 2, II is a shaft which may he saw ported in suitable bearings which are omitted in the figure for clearness; I2 is an armature for magnetic poles 8 and H1; l 3 is a magnetic circuit member processed into a permanent magnet, having a surface l4 spaced closely to rotor 2 to direct the flux of magnet l3 through rotor 2, then through stator and rotor poles to stator members 5 and 6, and thence to magnetie poles 8 and I0. Permanent magnet I3 has one l5, closely spaced to armature l2, so that the magnetic circuit of permanent magnet l3 may be completed through armature l2, to magnetic poles 8 or ill.

pring l6 may e emp under ns on or under compression by suitably end I thereof, and may be employed to holdarmaturg l2, either against pole 8, 01} against pole ID. i! and when desired.

Wedge I8 may be inserted into space l9, climb nating possible rotation of armature l2. and

such a case Fig. 1 becomes, in eifect, a simple motor with a rotor, which operates under electtrical impulses without the aid of a rocking m tu e- Battery 20 supplies current to lead 2|, when key 22 and supplies current to coil 1 through lead 28, when pressed to contact position.

Fig. 2, shaft i may be provided with a bearing 24, and an adjustment 25, to conven iently fix the length of the air-gap formed between the surface l4 and rotor 2.

Fig. 3 is an embodiment having a shaft II", a rotor I 02, stator members I 05 and 88, and a single coil I89 similar to the corresponding unitary numbered members of Fig. 1. In Fig. 3, stator member N15 is processed into a perma nent magnet and member I I3 is not permanently magnetized, but merely forms a return magnetic coil 8 through is lifted to contact position.

3 path for magnetic flux in stator member I05, and for magnetic flux in stator member I06 when current flows in coil I09, from battery I20, through leads I23 and I26, when key I22 is pressed to contact.

The magnetic circuit of Fig. 3 is completed through bar I2'I, which magnetically bridges the lower ends of stator members I and I05, as well as does it serve to bridge said stator members with central magnetic circuit member H3 at its lower end H5.

The magnetic flux in permanent magnetic stator member I05, flows mainly through bar I2'I, thence through member I I3, thence to rotor I02, and therefrom to member I05. The magnetic flux caused in member I05 by current in coil I09, flows through bar I2'I, thence through I21, thence through member II3, thence to rotor I02, and therefrom to member I05.

Before a detailed operation of Figs. 1, 2 and 3, can be traversed, a teaching of the structure of the poles employed in the stators and rotors of the figures must be set forth.

, It must be understood by those skilled in the art who undertake to embody this invention in practical devices, that when motor devices are made in sizes usually employed in the stepping switches, impulse counter and particularly in sizes useful in automobile clocks, that the fields of magnetic flux is sometimes greatly modified by the effect of what is termed stray or leakage flux, and the relative shapes and sizes of pol'e faces to cause a desired fiux distribution in one size of device may not give the same distribution if made on a different scale.

' Therefore in a patent specification only gen-- eral directions for forming poles can be given, and for precise performance, empirical determination following the general directions must be followed. The general teaching of the structure of the poles is given below.

In Figs. 5, 6, '7 and 8, the poles of the stators are laid out in a straight line instead of a circular line as is common practice in texts relating to the subject. For simplicity only two poles of rotor are shown, and the magnetic circuit return path is shown as a strip. The figures show only fragmentary parts of the stators, so that the pole faces can be enlarged to a size that is clearly suited to teaching the structure.

Referring to Fig. 5, 505 and 506 are fragmentary parts of the stator members of Figs. 1, 2, and 3, and 502 is a member which represents the rotor of the previous figures, but is considered to move linearly in an easterly direction, it has two pole faces 550 and SSL When one of these pole faces such as 55I, registers with a stator pole face such as 552, the other pole face 550, registers with an inter-polar space such as 553. The return circuit member 5I3 is considered stationary and in close relation with 502.

. In shaping the faces of the poles of the stator or in shaping the faces of the poles of the rotor individually or jointly the form to make is one which produces an unbalanced pull in one direction or the other by having the magnetic reluctanceto movement of the rotor in one direction less than the magnetic reluctance to movement in theother direction.

N Referring to Fig. 5, one side of the pole faces of 505 and 506 are rounded as shown at surfaces 5I4 and 5I5. This rounding of one side of the pole faces causes an unsymmetrical magnetic pull on the rotor member 502; and under a normal magnetic fieldcreated in 505, pulls member 502 to the east; though stray, shunted or leakage fiux in the magnetic circuit can cause member 502, to be pulled to the west. However if the pole faces have sufficient directively unsymmetrical mag netic reluctance the rotor will move in one direction and in that direction only.

Fig. 6 shows how directively unsymmetrical magnetic reluctance is obtained by forming the faces B50 and B5I, of the rotor 602. The poles of the stator members I505 and 606, may be symmetrical as shown or modified if desired in accordance with the teachings above.

Fig. '7 shows a further form of unsymmetrical pole faces, which may be employed as illustrated or in combination with the other pole face teachings given herein.

Fig. 8 shows forms of pole faces which are structurally symmetrical on both the rotor and on the stator; the unsymmetrical magnetic reluctance being obtained by shading coils, 810 and BI I, the operation of which is well understood in the art.

The detailed operation of Figs. 1, 2, and 3 will now be traversed with the understanding that any of the teachings set forth in connection with Figs. 5, 6, 7 and 8, may be applied to the struc tures shown in Figs. 1, 2, and 3. Different methods are suited to operating the structures disclosed in these figures and several will be traversed, others will be obvious to those skilled in the art.

Referring to Fig. l, with rotor 2 and armature I2 in the positions shown, and spring end ll loose;

rotor 2 is held in the position shown, by flux frompermanent magnet I3 flowing through armature I2, to magnetic pole 8, thence to the poles of stator member 5 which are in registration with the poles of rotor 2, through rotor 2 back to permanent magnet I3 through surface I4 (Fig. 2) thereof.

If key 22 is lifted to contact, the current through coil I0, closes the gap I9, by magnetic attraction the current in coil 9 is discontinued on breaking the coil circuit by allowing key 22 to assume its neutral position, shown in the figure. If key 22' is now pressed to contact, rotor 2, and armature I2, return to the positions shown in the figure. The operations may be repeated indefinitely with the result that with each alternate contact of key 22, the rotor 2, moves an angular distance equal to /2 the pole pitch of the stator and the rotor is held in any degree of angular displacement to which it is revolved. I

The movement of armature I2 is useful in driving electric clocks and the movement of the rotor is useful in indicating the time elapsed, if the electrical impulses fed to coils I and 9 are properly timed.

Obviously, the movement of the rotor is useful in counting the number of impulses that is received from any source, and the application of the invention is not a limitation thereof.

If spring bias" is applied to armature I2, by means of tension or compression from spring IS, the operation of Fig. 1 can be accomplished by current impulses in one of coils I or 9 without employing current impulses in both. One example will suffice to teach this embodiment.

If sufficient tension is applied to spring 16, by pulling westwardly on end I'I, armature I2 will assume the position shown in the figure in the absence of current in coil 9. If sufficient current is applied to coil 9, gap I9 will close as long as there is current in the coil, but sumcient spring tension will return to armature I2 to the position shown in the figure, in the absence of current in coil 9. The operation is thus; an impulse of current closes air-gap I9, and turns rotor 2 pole-pitch, on breaking the current in coil 9, armature I2 is pulled back to its starting position, and in so doing the fiux of permanent magnet I3, is causedto flow through stator member 5, which causes rotor 2 to turn an additional pole-pitch forward to a position corresponding with that shown in the figure. That is, under this condition of operation, for each impulse in one coil, two spacing operations are performed by rotor 2, and it is always held in the second spaced position, in the absence of coil current.

An additional method of operating the motor structure of Fig. 1, is by eliminating spring I6, and employing circuit diagram Fig. 4, in which one of the coils I, may be connected directly to battery 20., and the other of the coils 9 is connected simultaneously to battery 20, through a retarding circuit such as resistor 28 and capacitor 29. Momentary contact of key 22, causes this circuit to have a time difierence between the maximum fiux crests in the two circuits, causing two rotor spacings for each current impulse.

The operation of Fig. l with plug inserted in gap I9, is the same as with the plug out, except that there is no movement of armature I2, and magnetic circuit values are adjusted to give the same operation as with the plug out, which can be done empirically.

The operation of Fig. 3 is accomplished by the magnetized member I05 providing magnetic bias tion thereof, a third stator member located in in one stator member, much the same way as spring I6 causes normally a magnetic bias in stator member 5 of Fig. 1. That is, the magnetism of stator member I05, holds rotor I02 in the position shown in Fig. 3, with sufiicient current in coil I09, rotor I02 is turned polepitch, and on breaking the current in coil I09, the magnetism of member I05 turns rotor I02 an additional A. pole-pitch, so that for each current impulse in coil I09, two rotor spacings are obtained.

The expression polar structural means causing directionally unsymmetrical rotor air-gap reluctance is hereby defined to mean any embodiment of the teaching herein relating thereto and particularly the teaching in connection with Figs. 5-8 inclusive.

Also where the expression permanent magnet or a similar expression is used, electromagnets are a perfectly obvious equivalent thereof.

Several embodiments of the invention have been taught, but the nature of the invention is more clearly set forth in the claims hereunder.

What is claimed is:

1. In a motor device driven by direct current impulses, a rotor having salient poles, two stator members each having salient poles of an angular pitch equal to the pole-pitch of said rotor, one of said stator members having its poles rotated one-half pole-pitch from the angular periodic sequence of the poles of the other said member, all said poles formed to provide greater magnetic reluctance between the poles of the stator and the poles of the rotor for one direction of rotation thereof than for the other direction of rotation thereof, a third stator member located in between said two stator members dividing the magnetic fields of each of said two stator members through said rotor into two independently magnetizable stator magnetic circuits, two independent means for independently magnetizing said two magnetic circuits, one of said means being a source of constant magnetic flux included in a first of said two stator magnetic circuits, said flux attracting said rotor into a locked-rotor pole-position when extant, the other of said means being an electrically-excitable embracingcoil in a second of said two stator magnetic circuits and having a circuit including a switch with a source of direct current creating magnetic fiux in said second magnetic circuit impelling said rotor out of said locked-rotor pole-position to an advanced half-pole-pitch locked-rotor position, the magnitude of said attracting flux being sufiicient to hold said rotor in said locked posi tion when said switch is open, the magnitude of said impelling flux being suificient to pull said rotor out of said locked position to said advanced position when said switch is closed, and the magnitude of said attracting flux being also sufiicient to attract said rotor to an additional advanced half-pole-pitch locked-rotor position when said switch is opened after closing.

2. In a motor device driven by direct current impulses, a rotor having salient poles, two stator members each having salient poles of an angular pitch equal to the pole-pitch of said rotor, one of said stator members having its poles rotated onehalf pole-pitch from the angular periodic sequence of the poles of the other said member,

all said poles formed to provide greater magnetic reluctance between the poles of the stator and the poles of the rotor for one direction of rotation thereof than for the other direction of rotabetween said two stator members dividing the magnetic fields of each of said two stator members through said rotor into two independently magnetizable stator magnetic circuits, two independent means for independently magnetizing said two magnetic circuits, one Of said means being a permanent magnet source of constant magnetic flux included in a first of said two stator magnetic circuits, said flux attracting said rotor into a locked-rotor pole-position the other of said means being an electrically-excitable embracing-coil in a second of said two stator magnetic circuits and having a circuit including a switch with a source of direct current creating magnetic flux in said second magnetic circuit impelling said rotor out of said locked-rotor poleposition to an advanced half-pole-pitch lockedrotor position, the magnitude of said permanent magnetic fiux being sufiicient to hold said rotor in said locked position when said switch is open,

the magnitude of said impelling flux being sufilcient to pull said rotor out of said locked position to said advanced position when said switch is closed, and the magnitude of said permanent magnetic flux being also sufficient to attract said rotor to an additional advanced half-pole-pitch locked-rotor position when said switch is opened after closing.

3. In a motor device driven by direct current impulses, a rotor having salient poles, two stator members each having salient poles of an angular pitch equal to the pole-pitch of said rotor, one of said stator members having its poles rotated one-half pole-pitch from the angular periodic sequence of the poles of the other said member, all said poles formed to provide greater magnetic reluctance between the poles of the stator and the poles of the rotor for one direction of rotation thereof than for the other direction of rotation thereof, a third stator member located in between said two stator members dividing the magnetic fields of each of said two stator members through said rotor into two independently magnetizabie stator magnetic circuits, two independent means for independently magnetizing said two magnetic circuits, one of said means being an electrical source of constant magnetic flux included in a first of said two stator ma netic circuits, said flux attracting said rotor into a locked-rotor pole position when extant, the other of said means being an electrically-excitable embracing-coil in a second of said two stator magnetic circuits and having a circuit including a switch with a source of direct current creating magnetic flux in said second magnetic circuit impeiling said rotor out of said locked-rotor poleposition to an advanced half-pole-pitch lockedrotor position, the magnitude of said attracting flux being suflioient to hold said rotor in said locked position when said switch is open, the

20 magnitude of said impelling flux being suflicient to pull said rotor out of said locked position to 8 said advanced position when said switch is closed, and the magnitude of said attracting flux being also sufficient to attract said rotor to an additional advanced half-pole-pitch locked-rotor position when said switch is opened after closing.

MON'IFORD MORRISON.

References Cited in the file 01' this patent UNITED STATES PATENTS Number Name Date 788,762 Favarger May 2, 1905 1,405,502 Dodds Feb. 7, 1922 1,603,646 Sperry Oct. 19, 1926 2,081,411 Stroller et a1. May 25, 1937 2,249,029 Mullerheim July 15, 1941 2,321,699 OBrien June 15, 1943 2,499,316 Johnson Feb. 28, 1950 FOREIGN PATENTS Number Country Date 28,539 Great Britain of 1902 522,557 Great Britain June 20, 1940 

